1. Field of the Invention
The present invention relates to media systems and, more particularly, to media systems that support playlists.
2. Description of the Related Art
Media systems have permitted users to create playlists of audio tracks (i.e., songs) that are to be played. Typically, the media systems store a large library of audio tracks. Hence, the ability for a user to create their own playlists assists the user in playing those of the audio tracks from the library they prefer.
Conventionally, playlists have been created either by a drag-and-drop operation or by rules. A representative example of drag-and-drop playlist creation is the playlist creation of iTunes, version 1.0, from Apple Computer, Inc. of Cupertino, Calif. A representative example of a rules-based playlist creation is the playlist composer of SoundJam MP Plus published by Casady & Greene, Inc. of Salinas, Calif.
In the case of the drag-and-drop operation, the user selects one or more certain audio tracks from a list of audio tracks in a library. Then, the selected one or more tracks are dragged into a playlist. This drag-and-drop operation can be repeated until all the desired audio tracks have been dragged into the playlist. Later, such as after the audio tracks in the library are changed, the user can drag new audio tracks into or delete tracks from the playlist. Thus, the drag-and-drop operation requires user interaction and is particularly cumbersome for media systems that have a large library of audio tracks to choose from.
In the case of a playlist that is defined by rules, the playlist is created by a computing device selecting those of the audio tracks in the library that satisfy the rules. The user specifies the rules for the playlist. The rules are the criteria that are used to determine whether the audio tracks are to be included in the playlist. For example, a rule could include in the playlist all audio tracks listing “Pink Floyd” as artist. When the rules are processed by the computing device, the audio tracks satisfying the rules are placed in the playlist. Although the creation of the playlist is automated after the user specifies the appropriate rules, the playlist that is created is fixed. Unfortunately, since the audio tracks in libraries often change (e.g., new audio tracks added), the playlist that has been created soon becomes unreliable. For example, the playlist could easily not include certain of the subsequently added audio tracks in the library that satisfy the rules for the playlist. A user would be forced to either manually perform drag-and-drop operations with respect to the playlist or manually again specify rules and create a new playlist in order to have the playlist include all the audio tracks within the library that satisfy the rules for the playlist.
Thus, there is a need for improved techniques to maintain playlists within media systems.